1. Field of the Invention
This invention pertains to apparatus for fabricating a plurality of electrical harnesses. Each harness includes a connector defined by a two-part housing with one part having insulation displacement type terminals loaded therein, connected to an insulation clad wire, preferably a wire of the flat ribbon cable type. More particularly, the present invention relates to apparatus for producing sets of electrical harnesses defined by cable segment terminated to a plurality of electrical connectors, commonly termed "daisy-chain" harnesses.
2. Brief Description of the Prior Art
Manufacturers of electronic products are relying on electrical harnesses employing insulation displacement type contacts to avoid many of the inefficiences and costs associated with other types of electrical connections. A typical electrical harness that is now widely accepted includes a mass termination connector with a two-part housing in which one part has insulation displacement type terminals positioned therein. Some or all of the terminals are electrically connected to insulation clad wires of either the discrete wire type, or wires joined together in a unitary flat cable construction.
One example of a mass termination insulation displacement type connector is described in U.S. Pat. No. 4,410,222 assigned to the assignee of the present invention. The electrical connector assembly is comprised of two parts which, when telescopically mated one with another, form a termination with a multiconductor flat ribbon cable. Termination of the cable is accomplished by inserting the cable between a first connector part containing a plurality of insulation displacement terminals, and a second connector part comprising a mating cover which assists in the alignment of the flat cable with respect to the insulation displacing terminals. Compression of the two connector parts causes insertion of the several conductors of the flat cable in the insulation displacing terminals of the first connector part.
While the aforementioned patent describes a particular connector assembly having a third strain relief cover, such strain relief covers (requiring the cable to be folded over the connector cover) are not always needed in a given installation. In this event, termination of the cable to the two connector parts is accomplished simply by compressing the cable between those parts.
Electronic appliance manufacturers are employing daisy-chain harnesses to interconnect various circuit segments on a given printed circuit board, and to interconnect circuit portions of two or more circuit boards. Manufacturers are also packaging groups of circuit boards in a variety of angular positions and spaced relationships. As a result, the daisy-chain harnesses required for such appliances must have a variety of connector types oriented in a variety of positions. For example, mass termination connectors can be applied to a cable in either a first or a second orientation, such that the terminals project away from either flat cable surface. Further, a given ribbon cable harness assembly may be required to interconnect a variety of mass termination connectors of different circuit sizes, and different physical dimensions.
Several machines currently in use today for fabricating daisy-chain cable harnesses employ a movable termination head mounted for reciprocation along a track which overlies a serial succession of opposing stationary termination heads. Although connnector parts of different types can be located at each termination station, the reciprocating termination head can accommodate only one particular mating connector part (typically the cover). Connectors cannot be installed in an opposing (upside-down) direction.
If a greater variety of connector terminations is required for a given harness assembly, multiple termination stations, each having opposed termination heads can be provided in a serial array, coextensive with the cable of the harness assembly. Such arrangements are, however, quite costly due to the duplication of termination tooling involved, and in the floor space required for such machine installations. Further, in an automated arrangement, a substantial cost is involved in duplicating the feeding or loading stations for each termination station.
In an effort to provide more compact termination equipment installations, rotating carousel robots and rotating turrets have been employed. An example of a carousel robot is given in U.S. Pat. No. 4,050,764 wherein a given connector part is rotatably advanced past several tooling stations, one of which terminates the connector part to a wiring harness. The installation can accommodate only one particular connector assembly, and is not adapted for daisy-chain harness construction.
An example of a rotating turret employed in a cable termination arrangement is described in U.S. Pat. No. 4,367,575. The rotating turret carries a number of connector holders, all carrying the same connector part. The turret is stepped to bring a connector holder in alignment with a stationary tooling member holding the mating connector part. The turret arrangement increases the production rate of cable harness fabrication, and provides a convenient harness ejection arrangement by employing a second turret spaced apart from the first turret, but aligned on a common axis to operate at a unitary drum-like arrangement. Only a single connector type, with only one connector per harness is fabricated with this arrangement.